This is a very late addition to this thread but I've been working on an image view that supports zoom and pan and has a couple of features I haven't found elsewhere. This started out as a way of displaying very large images without causing OutOfMemoryErrors, by subsampling the image when zoomed out and loading higher resolution tiles when zoomed in. It now supports use in a ViewPager, rotation manually or using EXIF information (90° stops), override of selected touch events using OnClickListener or your own GestureDetector or OnTouchListener, subclassing to add overlays, pan while zooming, and fling momentum.

它不打算作为ImageView的一般使用替代品，因此不扩展它，并且不支持显示来自资源的图像，只支持资产和外部文件。它需要SDK 10。

源代码在GitHub上，有一个示例说明了在ViewPager中的使用。

https://github.com/davemorrissey/subsampling-scale-image-view

我刚刚整合了Robert Foss的TouchImageView:它完美地开箱即用!谢谢!

我只是修改了一些代码，所以我可以从我的layout.xml实例化它。

只需添加两个构造函数

public TouchImageView(Context context, AttributeSet attrs) {
    super(context, attrs);
    init(context);
}

public TouchImageView(Context context) {
    super(context);
    init(context);
}

并将旧的构造函数转换为init方法:

private void init(Context context){
    //...old code ofconstructor of Robert Moss's code
}

更新

我刚刚给TouchImageView一个新的更新。它现在包括双击缩放和抛除平移和捏缩放。下面的代码非常过时。你可以查看github项目以获得最新的代码。

使用

在项目中放置TouchImageView.java。这样就可以像 ImageView。例子:

TouchImageView img = (TouchImageView) findViewById(R.id.img);

如果你在xml中使用TouchImageView，那么你必须提供完整的包 名称，因为它是一个自定义视图。例子:

<com.example.touch.TouchImageView
    android:id="@+id/img”
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

注意:我已经删除了我之前的答案，其中包括一些非常旧的代码，现在直接链接到github上最新的代码。

ViewPager

如果你有兴趣把TouchImageView放在ViewPager中，请参考这个答案。

In Response to Janusz original question, there are several ways to achieve this all of which vary in their difficulty level and have been stated below. Using a web view is good, but it is very limited in terms of look and feel and controllability. If you are drawing a bitmap from a canvas, the most versatile solutions that have been proposed seems to be MikeOrtiz's, Robert Foss's and/or what Jacob Nordfalk suggested. There is a great example for incorporating the android-multitouch-controller by PaulBourke, and is great for having the multi-touch support and alltypes of custom views.

就我个人而言，如果你只是简单地绘制一个画布到一个位图，然后在ImageView中显示它，并希望能够使用多点触摸缩放和移动，我发现MikeOrtiz的解决方案是最简单的。然而，出于我的目的，他提供的Git代码似乎只在他的TouchImageView自定义ImageView类是唯一的子类或提供布局参数时才能工作:

android:layout_height="match_parent"
android:layout_height="match_parent"

不幸的是，由于我的布局设计，我需要“wrap_content”为“layout_height”。当我把它改成这样的时候，图像在底部被裁剪了，我不能滚动或缩放到裁剪的区域。 所以我看了一下ImageView的源代码，看看Android是如何实现“onMeasure”的，并改变MikeOrtiz的以适应。

   @Override
protected void onMeasure (int widthMeasureSpec, int heightMeasureSpec)
{
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

  //**** ADDED THIS ********/////
      int  w = (int) bmWidth;
      int  h = (int) bmHeight;
     width = resolveSize(w, widthMeasureSpec);  
     height = resolveSize(h, heightMeasureSpec);
  //**** END ********///   

   // width = MeasureSpec.getSize(widthMeasureSpec);   // REMOVED
   // height = MeasureSpec.getSize(heightMeasureSpec); // REMOVED

    //Fit to screen.
    float scale;
    float scaleX =  (float)width / (float)bmWidth;
    float scaleY = (float)height / (float)bmHeight;

    scale = Math.min(scaleX, scaleY);
    matrix.setScale(scale, scale);
    setImageMatrix(matrix);
    saveScale = 1f;

    // Center the image
    redundantYSpace = (float)height - (scale * (float)bmHeight) ;
    redundantXSpace = (float)width - (scale * (float)bmWidth);
    redundantYSpace /= (float)2;
    redundantXSpace /= (float)2;

    matrix.postTranslate(redundantXSpace, redundantYSpace);

    origWidth = width - 2 * redundantXSpace;
    origHeight = height - 2 * redundantYSpace;
   // origHeight = bmHeight;
    right = width * saveScale - width - (2 * redundantXSpace * saveScale);
    bottom = height * saveScale - height - (2 * redundantYSpace * saveScale);

    setImageMatrix(matrix);
}

这里的resolveSize(int,int)是一个实用程序，用于将所需的大小与MeasureSpec施加的约束进行协调，其中:

参数:

 - size How big the view wants to be
 - MeasureSpec Constraints imposed by the parent

返回:

 - The size this view should be."

本质上提供了一种行为更类似于图像加载时的原始ImageView类。还可以进行更多的更改，以支持修改纵横比的各种屏幕。但现在我希望这能有所帮助。感谢MikeOrtiz的原始代码，做得很好。

你也可以试试http://code.google.com/p/android-multitouch-controller/

这个图书馆真的很棒，尽管一开始有点难以理解。

如下所示就可以了。

@Override public boolean onTouch(View v,MotionEvent e)
{

    tap=tap2=drag=pinch=none;
    int mask=e.getActionMasked();
    posx=e.getX();posy=e.getY();

    float midx= img.getWidth()/2f;
    float midy=img.getHeight()/2f;
    int fingers=e.getPointerCount();

    switch(mask)
    {
        case MotionEvent.ACTION_POINTER_UP:
            tap2=1;break;

        case MotionEvent.ACTION_UP:
            tap=1;break;

        case MotionEvent.ACTION_MOVE:
            drag=1;
    }
    if(fingers==2){nowsp=Math.abs(e.getX(0)-e.getX(1));}
    if((fingers==2)&&(drag==0)){ tap2=1;tap=0;drag=0;}
    if((fingers==2)&&(drag==1)){ tap2=0;tap=0;drag=0;pinch=1;}

    if(pinch==1)

    {
        if(nowsp>oldsp)scale+=0.1;
        if(nowsp<oldsp)scale-=0.1;
        tap2=tap=drag=0;    
    }
    if(tap2==1)
        {
            scale-=0.1;
            tap=0;drag=0;
        }
    if(tap==1)
        {
            tap2=0;drag=0;
            scale+=0.1;
        }
    if(drag==1)
        {
            movx=posx-oldx;
            movy=posy-oldy;
            x+=movx;
            y+=movy;
            tap=0;tap2=0;
        }
    m.setTranslate(x,y);
    m.postScale(scale,scale,midx,midy);
    img.setImageMatrix(m);img.invalidate();
    tap=tap2=drag=none;
    oldx=posx;oldy=posy;
    oldsp=nowsp;
    return true;
}


public void onCreate(Bundle b)
{
        super.onCreate(b);

    img=new ImageView(this);
    img.setScaleType(ImageView.ScaleType.MATRIX);
    img.setOnTouchListener(this);

    path=Environment.getExternalStorageDirectory().getPath();   
    path=path+"/DCIM"+"/behala.jpg";
    byte[] bytes;
    bytes=null;
    try{
        FileInputStream fis;
        fis=new FileInputStream(path);
        BufferedInputStream bis;
        bis=new BufferedInputStream(fis);
        bytes=new byte[bis.available()];
        bis.read(bytes);
        if(bis!=null)bis.close();
        if(fis!=null)fis.close();

     }
    catch(Exception e)
        {
        ret="Nothing";
        }
    Bitmap bmp=BitmapFactory.decodeByteArray(bytes,0,bytes.length);

    img.setImageBitmap(bmp);

    setContentView(img);
}

为查看完整的程序看这里:程序放大图像在android